Sorry I did not update my post. I kind of forgot about it actually...
How did things go? They actually went rather well. I treated my poncho and the results were great. I gave it the ol' shower test again and did not have a wet backside for my efforts as I did previously.
A Couple of suggestions. If you are going to treat the fabric after the tarp or poncho is made it is a good idea to keep it pitched tight. I found a couple of spots that dried while touching each other that, when pulled apart, left a visual mark. I do not think this will effect the waterproofness of the poncho, it is just a little noticeable. I can not speak of the durability of this treatment since I have only used it once in actual rain. I cant see why it would not last a while. I have since changed my mind about poncho use (I am going to try to make something like a Packa now). The poncho I made weighs less than 8oz. If someone wants to test/have this piece of gear I will let it go for $20 (sorry...I know this is not the gear swap...
) It was my first poncho but I think it turned out ok.
Would I do the treatment method again.. Sure I would. I was not THAT hard at all really and it was dirt cheap.
Any more questions just ask.